Medical headlamp providers have attempted to make a single design that serves a variety of purposes, and in so doing have diminished the capability of such a design to perform any single specialized purpose. For example, many designs feature an adjustable iris, to permit a user to set the beam width of the light produced. Unfortunately, such an iris blocks a good deal of the light, thereby requiring a brighter light source, needing more power.
It is an undesirable expense, however, to purchase a separate head lamp assembly for each purpose that a physicians' office or hospital department may require. It would be desirable to find a way to eliminate at least part of this expense.